Connection handover handling

ABSTRACT

A method in a server for handling a connection between a mobile communication device and a second communication device, said server being connected to a wireless local area network and a wireless wide area network, said method comprising receiving a signal indicative of a status of the connectivity between said mobile communication device and said wireless local area network; and depending on said connectivity status, controlling a sticky handover process, wherein in a case the connectivity status of the connection between the mobile communication device and the wireless local area network is bad and the mobile communication device is connected to the wireless local area network, handing over the connection from the wireless local area network to said wireless wide area network; and in a case the connectivity status of the connection between the mobile communication device and the wireless local area network is good and the mobile communication device is not connected to the wireless local area network, handing over the connection to the wireless local area network is provided. A device and computer program product thereof is also provided.

TECHNICAL FIELD

The present invention relates to a method for handling a wirelessconnection and a server and computer program product thereof.

BACKGROUND

Mobile communication devices, such as mobile phones or personal digitalassistants (PDAs), are today used for many different purposes.

Most commonly such mobile communication devices have access only to onetype of network. A typical case is mobile phones only having access to amobile communications network of the Global System for Mobilecommunications (GSM) type. As is commonly known the GSM system is atypical example of a cellular network, said network comprising aplurality of covering cells served by base stations, which base stationsfacilitate the communication between the mobile communication device andthe network. As the mobile communication device moves from onegeographical location to another it will move from the covering cell ofa first base station to the covering cell of a second base station. Theprocess of handling the communication switch of the mobile communicationdevice from the first base station to the second base station is calleda handover.

Moreover, during recent years different types of wireless wide area aswell as local area networks have been developed and deployed. Examplesof wireless local area networks include wireless Voice over IP (VoIP,Voice over Internet Protocol) networks, WiMAX (WorldwideInteroperability for Microwave Access) networks, etc. Typically thewireless local area networks comprises covering cells served byso-called access points.

Mobile communication devices with functionalities for both wireless widearea networks, such as GSM, and wireless local area networks, such aswireless VoIP networks, have been introduced. However there is still aproblem with handover from wireless networks of different types. Thistype of handover is usually referred to as a vertical handover.

WO2005071998 discloses a method for performing a vertical handover of awireless voice connection, wherein the decision for performing thehandover is based on a set of handover factors. Hence WO2005071998discloses a method for determining when such a vertical handover may beperformed. However the problem of how to perform such a verticalhandover in an efficient manner still remains. Typically, methods forvertical handovers cannot deploy known handover techniques which havebeen established for handovers within one single network, such as theabove example regarding handovers in a GSM system. In view of the above,the invention seeks to solve or at least reduce the problems discussedabove. In particular, to the invention provides a method for handling aconnection between a mobile communication device and a secondcommunication device via a server.

BRIEF SUMMARY

Hence there is provided a method in a server for handling a connectionbetween a mobile communication device and a second communication device,wherein the server is connected to a wireless local area network and awireless wide area network, wherein the method comprises receiving asignal indicative of a status of the connectivity between the mobilecommunication device and the wireless local area network; and

depending on the connectivity status, controlling a sticky handoverprocess, wherein in a case the connectivity status of the connectionbetween the mobile communication device and the wireless local areanetwork is bad and the mobile communication device is connected to thewireless local area network, handing over the connection from thewireless local area network to said wide area wireless network; and in acase the connectivity status of the connection between the mobilecommunication device and the wireless local area network is good and themobile communication device is not connected to the wireless local areanetwork, handing over the connection to the wireless local area network.

Thus, such a method allows for a seamless handover between wirelesslocal area networks and wireless wide area networks, or in other wordsfor seamless roaming between disparate networks. Moreover the method hasthe additional advantage of being centralized in a server which is incontact with both the wireless local area network and the wireless widearea network throughout the duration of the connection.

The signal indicative of a status of the connectivity between the mobilecommunication device and the wireless local area network may be composedof one or more packets of data. It may further comprise a stream ofdata. Furthermore, the term Òindicative of a statusÓ should in thiscontext be interpreted widely; any measurement, calculation,characterization and/or interpretation of the connectivity status asgood or bad may either be performed in the server or in the mobilecommunication device. Moreover the connectivity status may be acombination of the connectivity status as estimated by the server andthe connectivity status as estimated by the mobile communication device.

The method may further comprise associating the mobile communicationdevice with a wireless local area network address; associating themobile communication device with a unique identity in a wireless widearea network; and storing the address and the unique identity.

Hence identification information pertaining to the mobile communicationdevice is stored in the server which enables the connection between themobile communication device and a second communication device to beanchored in the server.

In the case the connectivity status of the connection between the mobilecommunication device and the wireless local area network is bad and themobile communication device is connected to the wireless local areanetwork, the sticky handover process may further comprise determiningthe unique identity of the mobile communication device using thewireless local area network address of the mobile communication device;initiating the wireless wide area network connection from the server tothe mobile communication device using the unique identity; establishinga connection between the mobile communication device and the secondcommunication device via the server, wherein the connection between themobile communication device and the server is a connection in thewireless wide area network; terminating the wireless local area networkconnection between the mobile communication device and the server; andin the case the connectivity status of the connection between the mobilecommunication device and the wireless local area network is good and themobile communication device is not connected to the wireless local areanetwork, the sticky handover process may further comprise determiningthe wireless local area network address of the mobile communicationdevice using the unique identity of the mobile communication device;initiating the wireless local area network connection from the server tothe mobile communication device using the wireless local area networkaddress; establishing a connection between the mobile communicationdevice and the second communication device via the server, wherein theconnection between the mobile communication device and the server is aconnection in the wireless local area network; and terminating thewireless wide area network connection between the mobile communicationdevice and the server.

The method may further comprise detecting that the connection betweenthe mobile communication device and the wireless local area network islost; determining the unique identity of the mobile communication deviceusing the wireless local area network address of the mobilecommunication device; and as a consequence of the detection using theunique identity to perform the sticky handover of the connection fromthe wireless local area network to the wireless wide area network.

Hence, such a method prevents an unexpected loss of connection in awireless local area network by seamlessly handing over the connection toa wireless wide area network. This is made possible since identificationinformation of the mobile communication device in both the wirelesslocal area network and the wireless wide area network is stored in theserver

The method may further comprise indicating to the second communicationdevice a temporary loss of connection pertaining to the detection of alost connection between the mobile communication device and the wirelesslocal area network. Such an indication may e.g. take the form of apre-recorded voice message. Hence the proposed method possesses theadded advantage of increasing the user experience since the risk ofhaving a loss of connection is significantly reduced.

The signaling between the mobile communication device and the server mayutilize GPRS (General Packet Radio Service) in a case the mobilecommunication device is connected to the server via a wireless wide areanetwork. Furthermore the traffic data communication between the mobilecommunication device and the server may utilize GPRS in a case themobile communication device is connected to the server via a wirelesswide area network.

Thus a further advantage is the ability only to utilize the capabilitiesfor transmitting e.g. voice as packet data over GPRS instead ofestablishing a common voice connection.

The wireless local area network may be one of a plurality of availablewireless local area networks including: any IEEE 802.11x network(Institute of Electrical and Electronics Engineers), WiMAX, Bluetooth;the wireless wide area network may be one of a plurality of availablewireless wide area networks comprising: UMTS (Universal MobileTelecommunications System), GPRS, EDGE (Enhanced Data rates for GSMEvolution), GSM; and the wireless local area networks and the wirelesswide area networks may be prioritized according a specific order.

Hence the method enables a choice of a preferred network from aplurality of networks. For example the wireless local area networks andthe wireless wide area networks may be prioritized according to theorder: 1) IEEE 802.11x, 2) WiMAX, 3) UMTS, 4) GPRS, 5) EDGE, 6) GSM, 7)Bluetooth. Not all of these networks may be available at a specificlocation and/or at a specific time period. Note that the invention isnot limited to a particular set of existing wireless networks; theinvention is also applicable to any new mobile radio technology whichinvolves handover from a first type of wireless network to a second typeof wireless network.

According to another aspect there is also provided a method in a mobilecommunication device, comprising associating the mobile communicationdevice with a unique identity in a wireless wide area network; receivingclient information; associating the client information with a wirelesslocal area network address; configuring the mobile communication devicefor communication over a plurality of wireless local area networks and aplurality of wireless wide area networks; receiving a signal indicativeof a sticky handover from the server; and depending on the signalperforming a sticky handover process, wherein in a case the mobilecommunication device is connected to the server via the wireless localarea network switching the connection from the wireless local areanetwork to a wireless wide area network; and in a case the mobilecommunication device is connected to the server via a wireless wide areanetwork switching the connection from the wireless wide area network tothe wireless local area network.

Hence one advantage with the proposed method is that although the mobilecommunication device may be capable of operating in a plurality ofdifferent networks only one identity, such as a phone number, is neededin order for a user of a second communication device to contact a userof said mobile communication device. Thus the user of the mobilecommunication device have access to the sum of the functionalities inall accessible wireless networks (where available).

The method in a mobile communication device may further comprisedetecting that the connection between the mobile communication deviceand the wireless local area network is lost; waiting for a signalindicative of a new connection whilst remaining in a standby mode; andindicating a temporary loss of connection pertaining to said detectionof a lost connection between the mobile communication device and thewireless local area network.

Hence a method for preventing a loss of connection in a wireless localarea network is proposed. A similar method may also be applied in case aloss of connection in a wireless wide area network is detected. Againthe proposed method possesses the added advantage of increasing the userexperience since the risk of having a loss of connection issignificantly reduced.

The method in a mobile communication device may further comprisemeasuring a signal indicative of a status of the connectivity betweenthe mobile communication device and a server via the wireless local areanetwork; and transmitting information pertaining to the measured signalto said server.

Note that in contrast to the method in a server as described above themobile communication device is not arranged to receive a signalindicative of a status of the connectivity between the mobilecommunication device and a server via the wireless local area network;the mobile communication device may measure and then transmitinformation pertaining to the measured signal to the server.

According to yet another aspect there is provided a server comprisingcircuitry configured to receive a signal indicative of a status of theconnectivity between said mobile communication device and said wirelesslocal area network; and depending on said connectivity status, control asticky handover process, wherein in a case the connectivity status ofthe connection between the mobile communication device and the wirelesslocal area network is bad and the mobile communication device isconnected to the wireless local area network, hand over the connectionfrom the wireless local area network to said wide area wireless network;and in a case the connectivity status of the connection between themobile communication device and the wireless local area network is goodand the mobile communication device is not connected to the wirelesslocal area network, hand over the connection to the wireless local areanetwork.

Hence such a server carries out a method in a server as discussed above.

Finally, there is also provided a computer program product, comprisingcomputer program code stored on a computer-readable storage mediumwhich, when executed on a processor, carries out a method in a mobilecommunication device as described above, and a computer program product,comprising computer program code stored on a computer-readable storagemedium which, when executed on a processor, carries out a method in aserver as described above.

Other features and advantages of the present invention will appear fromthe following detailed disclosure, from the attached dependent claims aswell as from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The above, as well as additional features and advantages of the presentinvention, will be better understood through the following illustrativeand non-limiting detailed description of preferred embodiments of thepresent invention, with reference to the appended drawings, where thesame reference numerals will be used for similar elements, wherein:

FIG. 1 is a schematic illustration of a communication system, as anexample of an environment in which the present invention may be applied.

FIG. 2 is a schematic front view illustrating a multi-mode mobilecommunication device according to an embodiment.

FIG. 3 is a schematic block diagram representing an internal component,software and protocol structure of the mobile terminal shown in FIG. 2.

FIG. 4 a is flow chart illustrating a method in a server for handling aconnection between a mobile communication device and a secondcommunication device.

FIGS. 4 b-c are flow charts illustrating methods for a sticky handoverprocess according to embodiments.

FIG. 5 is a flow chart illustrating a method in a mobile communicationdevice for facilitating a sticky handover process according to anembodiment.

FIG. 6 is a flow chart illustrating a method for handling a connectionbetween a mobile communication device and a second communication devicevia a server according to an embodiment.

DETAILED DESCRIPTION

FIG. 1 illustrates an example of a communications system 100 in whichthe invention may be applied. In the communications system 100 of FIG.1, various telecommunications services such as cellular voice calls,www/wap browsing, cellular video calls, data calls, facsimiletransmissions, music transmissions, still image transmissions, videotransmissions, electronic message transmissions, general datatransmission, electronic positioning information, and electroniccommerce may be performed between a multi-mode mobile communicationdevice 115 according to the present invention and other communicationdevices, which devices are not explicitly shown in the figure. It is tobe noted that for different embodiments of the mobile terminal 115 andin different situations, different ones of the telecommunicationsservices referred to above may or may not be available; the invention isnot limited to any particular set of services in this respect.

The multi-mode mobile communication device 115 is able to communicatelocally via a wireless local area communications network 130 through aradio link 110 and via an access point 105. As is known to a personskilled in the art wireless local area networks, such as the network130, may comprise a plurality of access points, of which only one accesspoint 105 is shown in the figure. The access point 105 is operativelyconnected to the wireless local area network 130. The wireless localarea network 130 may be in compliance with any commercially availablewireless local area networks (WLAN) standard, such as any of the IEEE802.11x standards, WiMAX, or Bluetooth.

The multi-mode mobile communication device 115 is also operativelyconnected to a wireless wide area communications network 145 through aradio link 120 and via a base station 125. The base station 125 isoperatively connected to the wireless wide area network 145. As is knownto a person skilled in the art wireless wide area networks, such as thenetwork 145, commonly comprises a plurality of base stations, of whichonly one base station 125 is shown in the figure. The wireless wide areanetwork 145 may be in compliance with any commercially available mobiletelecommunications standard, such as GSM, UMTS, D-AMPS (Digital-AdvancedMobile Phone Service), CDMA2000 (Code division multiple access), FOMA(Freedom of Mobile Multimedia Access) and TD-SCDMA (TimeDivision-Synchronous Code Division Multiple Access).

A common public switched telephone network (PSTN) 150 is connected tothe wide area communications network 145 in a manner known to a personskilled in the art. Various communication terminals (not shown inFIG. 1) are commonly connected to the PSTN 150, the wireless wide areanetwork 145 and the wireless local area network 130.

A multi-mode gateway server 135 is connected to both the wireless localarea network 130 and the wireless wide area network 145, wherein theconnection between the multi-mode gateway server 135 and the wirelesswide area network 145 is via the PSTN 150. Said server handles thewireless connection to and from the multi-mode mobile communicationdevice 115 via either the wireless local area network 130 or via thewireless wide area network 145.

The server 135 may handle identification parameters for identifying themobile communication device 115 in at least said wireless local areanetwork 130 and at least said wireless wide area network 145. As will bedescribed in more detail below said identification parameters maycomprise e.g. a wireless local area network address in said wirelesslocal area network and a unique identifier in said wireless wide areanetwork 145. Thus at any point of the connection stage the server holdsinformation regarding the identity of the mobile communication device inwireless networks in which the multi-mode mobile communication devicehas been configured to operate. Moreover all connections to and fromsaid multi-mode mobile communication device passes through said serversince it is associated with the identity in form of e.g. a phone numberof said multi-mode mobile communication device, which phone number auser of the second communication device may use to contact a user ofsaid multi-mode mobile communication device. That is, the user of thesecond communication device dials said phone number and said serverassociates said phone number with said corresponding wireless local areanetwork address and/or said unique identifier, thereby establishing aconnection from said second communication device to said multi-modemobile communication device via said server.

Hence all connections to and from said multi-mode mobile communicationdevice may be characterized as being anchored in the multi-mode gatewayserver 135. The server 135 has a data storage 140 in which saididentification parameters of the multi-mode mobile communication devicemay be stored.

At least one multi-mode mobile communication device 115 capable ofcommunicating with a server 135 and at least one such a server 135comprising circuitry to perform said method for anchoring a connectionin a server will together with the communications system 100 thusaccording to one aspect of the present invention provide a system forhandling a wireless connection, which connection is transformed througha plurality of wireless networks of different types. Hence saidcommunications system 100 facilitates the communication between said atleast one multi-mode mobile communication device 115 and said at leastone server 135.

An embodiment 200 of the multi-mode mobile communication device 115 isillustrated in more detail in FIG. 2. The multi-mode mobilecommunication device 200 may be e.g. a mobile phone or a personaldigital assistant (PDA). The multi-mode mobile communication device 200comprises a display 210, a speaker 230, a microphone 220, antennas 205,225, and a keypad 215 comprising a set of keys. The two antennas merely205, 225 symbolizes that the mobile communication device 200 is ofmulti-mode type, i.e. that the device is capable of communicating with amultitude of different wireless networks using a plurality of differentcommunication modes, such as different protocol standards, e.g. both GSMand VoIP. The multi-mode mobile communication device 200 may furthercomprise e.g. a digital camera and/or other functionalities or featuresnot explicitly illustrated in connection with the description of FIG. 2.

The internal components 300, software and protocol structures of themulti-mode mobile communication device 200 will now be described withreference to FIG. 3. The multi-mode mobile communication device has acontroller 335 which is responsible for the overall operation of themobile terminal under the supervision of an operating system, whichinstructions preferably are implemented in a commercially availablecentral processing unit (CPU) 320, such as a digital signal processor(DSP).

The controller 335 has associated electronic memory 330 such as RAM(Random Access Memory), ROM (Read Only Memory), EEPROM (ElectricallyErasable Programmable Read-Only Memory), flash memory, or anycombination thereof The memory 330 is used for various purposes by thecontroller 335, one of them being storing data and program instructionsfor various software in the mobile terminal.

The software includes a real-time operating system, drivers for a userinterface (UI) 315, an application handler as well as variousapplications. The applications can include a messaging application forsending and receiving SMS (Short Message Service), MMS (MultimediaMessaging Service) or email, a media player application, as well asvarious other applications, such as applications for voice calling,video calling, www/wap browsing, an instant messaging application, aphone book application, a calendar application, a control panelapplication, a camera application, one or more video games, a notepadapplication, a positioning application, etc.

The UI 315 also includes one or more hardware controllers, whichtogether with the UI drivers cooperate with the display 210, keypad 215,motion sensor, as well as various other I/O devices such as themicrophone 220, the speaker 230, vibrator, ringtone generator, LED(Light Emitting Diode) indicator, etc. As is commonly known, the usermay operate the mobile terminal through the user interface thus formed.

The applications 310 may comprise a software client for handling atleast part of the mobile communication deviceÕs 115, 200 signalingbetween the mobile communication device 115, 200 and the multi-modegateway server 135 in FIG. 1. Said signaling may comprise informationexchange pertaining to a handover situation between two wirelesscommunication networks of different types. As a result of said signalingthe client software may forward various instructions to the controller335 for further processing by the operating system and the processor320. Similarly said client may interpret data from a signal indicativeof a status of the connectivity between the mobile communication device115, 200 and the server 135 via said wireless local area network 130.Said signal being communicated to the client application from a commoncommunications interface 305.

The client software may be provided by the manufacturer of the mobilecommunication device, or by at least one telecommunications networkoperator, or it may be downloaded to the mobile communication devicefrom a provisioning/configuration server. The client software may alsobe adapted for different telecommunication operators and/or differenttypes of mobile communication devices. Said provisioning/configurationserver may be operatively connected to either the wireless wide areanetwork or the wireless local area network or both. The client softwareprovides the mobile communication device with e.g. a wireless local areanetwork address.

The client and server should preferably be configured with specificparameters to function correctly. This is typically done by entering theconfiguration parameters directly on the device, from a console attachedto the device, or by using an element manager that is specific to eachtype of device. In order to ease the configuration and subsequentprovisioning of both the client and the server application, aprovisioning server may be included as part of a system solution. Theprovisioning server includes logic to ensure that the client and serverconfiguration is indeed synchronized such that it will interact andfunction correctly. In addition to ensuring correct configuration, theprovisioning server is also able to facilitate downloading of the clientapplication to various handsets using various handset providersÕspecific methods for OTA (Over The Air) provisioning. The provisioningserver may include client specific code from handset manufacturer SDKÕs(Software Development Kit).

The communications interface 305 comprises e.g. transport, network andconnectivity for at least a radio frequency interface for wireless widearea network access and a at least one interface for local connectivity,such as Bluetooth, IrDA (Infrared Data Association), WLAN (wirelesslocal area network) access, WiMAX, etc. As is commonly known thecommunications interface 305 comprises various modules, protocol stacks,drivers, circuitry, hardware components such as antennas, etc., forfacilitating said wide area and local area network access andcommunication. As is well known to a person skilled in the art, thecircuitry comprises a series of analogue and digital electroniccomponents, together forming a radio receiver and transmitter.

The multi-mode mobile communication device 200 as represented by theinternal components 300 in FIG. 3 may also have a SIM (SubscriberIdentity Module) card 325 and an associated reader. As is commonlyknown, the SIM card 325 comprises a processor as well as local work anddata memory. Information on said SIM card 325 may be used to associatesaid mobile communication device 115, 200 with a unique identity in awireless wide area network 145.

Continuing now with FIG. 4 a which is a flow chart illustrating a methodin the server 135 for handling a connection between a mobilecommunication device 115 and a second communication device.

The server 135 establishes a connection 410 between the mobilecommunication device 115 and the server 135. During the communicationbetween said server and said mobile communication device the serverreceives 415 a signal indicative of a status of the connectivity betweensaid mobile communication device and said wireless local area network130. The signal indicative of a status of the connectivity between themobile communication device and the wireless local area network mayinclude one or more packets of data. It may further comprise a stream ofdata. The signal indicative of the connectivity status may eithercomprise connectivity information as measured by the mobilecommunication device. However in a preferred embodiment any measurement,calculation, characterization and/or interpretation of the connectivitystatus is performed directly in the server. Based on said signal theserver may decide 420 whether or not the wireless local area network 130is available for communication with said mobile communication device.

The signal indicative of the status of the connectivity between themobile communication device and the wireless local area network maypertain to at least one property selected from: the position andmovement of the mobile communication device, the collected statistics oflost and retained connections for the position of the mobilecommunication device, the bit error rate between the mobilecommunication device and the wireless local area network, the signalstrength between the mobile communication device and the wireless localarea network, the number of lost packets between the mobilecommunication device and the wireless local area network, the number ofretransmitted packets between the mobile communication device and thewireless local area network, the signal-to-noise ratio between themobile communication device and the wireless local area network, thejitter of the signal between the mobile communication device and thewireless local area network, the latency of the signal between themobile communication device and the wireless local area network, etc.

By comparing said at least one property with at least one suitablethreshold the status may then be classified as either good or bad. Forexample if the estimated, expected, or measured value of the bit errorrate between the mobile communication device and the wireless local areanetwork is below a pre-defined threshold the connection may beclassified as good; otherwise the connection may be classified as bad.In addition it may be required for the said at least one property toremain above or below said threshold during at least a minimum timeperiod, e.g. in order for the connection to be classified as good saidbit error rate may be required to remain below said threshold duringsaid minimum time period.

In a case the connectivity status of the connection between the mobilecommunication device and the wireless local area network is good theserver 135 determines 425 from the signaling from the mobilecommunication device 115 whether or not the mobile communication device115 is operatively connected to the wireless local area network 130. Ina case the mobile communication device is not operatively connected tothe wireless local area network the server facilitates a sticky handover430 from the wireless wide area network 145 to the wireless local areanetwork 130. More details regarding the sticky handover process will begiven below with reference to FIG. 4 b. In a case the mobilecommunication device already is operatively connected to said wirelesslocal area network the server waits for another signal from the client.

In a case the connectivity status of the connection between the mobilecommunication device and the wireless local area network is bad theserver 135 determines 445 from the signaling from the mobilecommunication device 115 whether or not the mobile communication 115device is operatively connected to the wireless local area network 130.In a case the mobile communication device is operatively connected tothe wireless local area network the server facilitates a sticky handover450 from the wireless local area network 130 to the wireless wide areanetwork 145. In a case the mobile communication device already isoperatively connected to said wireless wide area network the serverwaits for another signal from the client.

The above procedures are repeated until the connection is terminated 435and the application may be stopped. It is here assumed that thetermination process is initiated by either the user of the mobilecommunication device 115 or the user of the second communication device.The case in which a connection is abruptly terminated due to networkconditions will be considered below with reference to FIG. 6.

With reference to FIGS. 4 b-c the sticky handover process will now bedescribed in greater detail. Specific details pertaining to the case inwhich the handover is from a wireless local area network to a wirelesswide area network will be considered in FIG. 4 b, whereas specificdetails pertaining to the case in which the handover is from a wirelesswide area network to a wireless local area network will be considered inFIG. 4 c.

If a handover process from the wireless local area network to thewireless wide area network has been decided (FIG. 4 b) the uniqueidentity (as discussed above with reference to FIG. 3) of the mobilecommunication device is determined 460 using the wireless local areanetwork address of the mobile communication device. Since the mobilecommunication device 115 is currently operatively connected to theserver 135 via the wireless local area network 145 said wireless localarea network address is known to the server 135. The server may thusfind said unique identity of the mobile communication device e.g. byperforming a table look-up in a data base, which data base may becomprised in the memory 140 of the server 135. Using said uniqueidentity of the mobile communication device the server may initiate 465a wireless wide area network connection from the server 135 to themobile communication device 115 using said unique identity. Thus awireless wide area network connection has thus been formed from theserver to the mobile communication device. A connection between saidmobile communication device 115 and said second communication device viasaid server may then be established 470 since said second communicationdevice is operatively connected to the server 135 during the entireduration of the communication between the mobile communication deviceand the second communication device. When the connection between saidmobile communication device 115 and said second communication device hasbeen established the wireless local area network connection between themobile communication device and the server may be terminated 475.

If a handover process from the wireless wide area network to thewireless local area network has been decided (FIG. 4 c) the wirelesslocal area network address (as discussed above with reference to FIG. 3)of the mobile communication device is determined 480 using the uniqueidentity of the mobile communication device. Since the mobilecommunication device 115 is currently operatively connected to theserver 135 via the wireless wide area network 130 said unique identityis known to the server 135. The server may thus find said wireless localarea network address of the mobile communication device e.g. byperforming a table look-up in a data base, which data base may becomprised in the memory 140 of the server 135. Using said wireless localarea network address of the mobile communication device the server mayinitiate 485 a wireless local area network connection from the server135 to the mobile communication device 115 using said wireless localarea network address. Thus a wireless local area network connection hasthus been formed from the server to the mobile communication device. Aconnection between said mobile communication device 115 and said secondcommunication device via said server may then be established 490 sincesaid second communication device is operatively connected to the server135 during the entire duration of the communication between the mobilecommunication device and the second communication device. When theconnection between said mobile communication device 115 and said secondcommunication device has been established the wireless wide area networkconnection between the mobile communication device and the server may beterminated 495.

A method in a mobile communication device for facilitating a stickyhandover process will now be described with reference to the flow chartof FIG. 5. The mobile communication device 115 is associated 510 with aunique identity in a wireless wide area network. This unique identitymay be e.g. a mobile phone number of the mobile communication device115. To enable a sticky handover functionality client information isreceived 515. The software pertaining to said client furthermoreassociates 520 said client information with a wireless local areanetwork address, which address e.g. may be an internet protocol (IP)address. The client software may further configure 525 said mobilecommunication device to settings for communications over a plurality ofdifferent wireless wide area, as well as local, networks. The client mayalso allow for user defined settings, for example allowing a user tospecify a list of preferred networks.

When a connection between the mobile communication device 115 and theserver 135 is established and an ongoing communication takes place 530the mobile communication device may measure 535 a signal indicative of astatus of the connectivity between said mobile communication device andsaid server via a wireless local area network. Information pertaining tosaid measured signal is transmitted 540 to said server at pre-definedintervals. The mobile communication device receives 545 a signalindicative of a sticky handover from said server, which signalÕs contentis based on the serverÕs interpretation of said transmitted information.Note that it may also be possible for the measurement, etc. to beperformed directly in the server 135. In this case steps 535 and 540 maybe omitted. Depending on said signal the mobile communication devicedecides 550 whether or not to perform a sticky handover process. In acase a handover is not needed the ongoing communication proceeds 530.

In a case the mobile communication device is connected to the server viasaid wireless local area network the client initiates a connectionswitch 560 from said wireless local area network to said wireless widearea network. In a case the mobile communication device is connected tothe server via said wireless wide area network the client initiates aconnection switch 570 from said wireless wide area network to saidwireless local area network. The switch is supervised by the controller335 in the mobile communication device 115, 200, 300.

The above procedures are repeated until the connection is terminated 565and the application may be stopped. It is here assumed that thetermination process is initiated by either the user of the mobilecommunication device 115 or the user of the second communication device.The case in which a connection is abruptly terminated due to networkconditions will be described next with reference to FIG. 6.

The flow chart of FIG. 6 describes in detail the handling of aconnection between a mobile communication device and a secondcommunication device via a server. A connection is requested 604 fromeither the mobile communication device or said second communicationdevice. As a result of said request it is investigated 606 whether ornot the mobile communication device has access to a wireless local areanetwork. If not, a wireless wide area network connection is initiatedand established 630.

If the mobile communication device has access to a wireless local areanetwork it is investigated 608 whether or not the mobile communicationdevice is logged on to said accessed wireless local area network. Ifnot, a wireless wide area network connection is initiated andestablished 630. If the mobile communication device is logged on to saidwireless local area network it is investigated 610 if the client islogged on to a SIP (Session Initiation Protocol) server. If not, awireless wide area network connection is initiated and established 630.If the client is logged on to a SIP server a connection between saidmobile communication device and said second communication device isestablished 612 via said server thus resulting in an ongoing 614wireless local area network connection between said mobile communicationdevice and said server.

During the ongoing connection in the wireless local area network anumber of checking steps will be carried out (not necessarily in theorder according to the below). If a signal indicative of a terminationis received 616 the connection is terminated 618. If not it isinvestigated 622 whether or not a handover situation pertaining to ahandover from the wireless local area network to the wide area network.If such a handover situation is detected a wireless wide area networkconnection is initiated and established 624 and the connection is handedover 626 to the wireless wide area network connection. Thus the ongoingconnection continues as a wireless wide area network connection (asindicated by the notation (B)-(B) from 628 to 628Õ in FIG. 6). If awireless local area network connection is still available it isinvestigated 654 whether or not the connection is unexpectedly lost.

An unexpectedly loss of connection may be defined as a connection whichis lost without a prior indication of termination from either the clientor the server. A typical example includes a case in which a mobilecommunication device currently located at a first location and connectedto a wireless local area network moves too fast from said first locationto a second location, in which location a valid wireless local areanetwork is not available, for a sticky handover to be performed. Asecond example includes a case in which a mobile communication devicecurrently located at a first location and connected to a wireless widearea network temporarily moves to a second location, in which location avalid wireless wide area network is not available due to e.g. a fadingdip.

If the connection is unexpectedly lost a loss of connection may beindicated 656 from the client to the user of the mobile communicationdevice and/or from the server to the user of the second communicationdevice. Thus such an unexpected loss of connection may be detected byboth the client and the server. The indication may e.g. take the form ofa pre-recorded voice message which may state that the connection istemporarily lost but that the connection will be re-established againand that no action is required by the user(s).

The connection may be re-established 658 as a wireless wide areaconnection. This is possible since before the unexpected loss ofconnection the mobile communication device 115 was operatively connectedto the server 135 via the wireless local area network 145, the wirelesslocal area network address of the mobile communication device is knownto the server 135. The server may thus find the unique identity of themobile communication device e.g. by performing a table look-up in a database, which data base may be comprised in the memory 140 of the server135. Using said unique identity of the mobile communication device theserver may initiate and establish 658 a wireless wide area networkconnection from the server 135 to the mobile communication device 115using said unique identity. Whilst awaiting a signal indicative of a newconnection between said mobile communication device and said server themobile communication device may remain in a standby mode. Thus theongoing connection continues as a wireless wide area network connection632 (as indicated by the notation (B)-(B) from 628 to 628Õ in FIG. 6).If the connection is not unexpectedly lost the ongoing connectioncontinues 614 in the wireless local area network.

If a wireless wide area network connection has been established 630 theconnection continues as an ongoing wireless wide area network connection632. During the ongoing connection in the wireless wide area network anumber of checking steps will be carried out (not necessarily in theorder according to the below). If a signal indicative of a terminationis received 634 the connection is terminated 636. If not it isinvestigated 638 whether or not the mobile communication device hasaccess to a wireless local area network. If the mobile communicationdevice has access to a wireless local area network it is investigated640 if the client is logged on to a SIP server.

If the client is logged on to said SIP server a wireless local areanetwork connection between the mobile communication device and theserver 135 is initiated and established 642. When said wireless localarea network connection has been established said server 135 facilitatesthe handover process 644 of the connection from the wireless wide areanetwork to the wireless local area network, and the wireless wide areanetwork is terminated 646. Thus the ongoing connection continues as awireless local area network connection 614 (as indicated by the notation(A)-(A) from 648 to 648Õ in FIG. 6).

If the mobile communication device does not have access to a wirelesslocal area network or if the client is not logged on to a SIP server itis investigated 650 whether or not the wireless wide area connection isunexpectedly lost. If the connection is unexpectedly lost a loss ofconnection may be indicated 652 from the client to the user of themobile communication device and/or from the server to the user of thesecond communication device. Thus such an unexpected loss of connectionmay be detected by both the client and the server.

The connection may be re-established 630 as a (new) wireless wide areaconnection. This is possible since before the unexpected loss ofconnection the mobile communication device 115 was operatively connectedto the server 135 via the wireless wide area network 145, the uniqueidentity of the mobile communication device is known to the server 135.The server may thus use the same said unique identity to initiate andestablish 630 a (new) wireless wide area network connection from theserver 135 to the mobile communication device 115 using said uniqueidentity. Thus the ongoing connection continues as a (new) wireless widearea network connection 632. It should be noted that although thewireless wide area network connection can be regarded as new, the userof the mobile communication device will not have to re-establish aconnection, e.g., by dialing a number. This functionality isautomatically handled by the server 135. However as is known to a personskilled in the art it may not always be possible to establish such a(new) wireless wide area connection due to the conditions of thewireless wide area network.

In summary, mobile phone numbers (for both wide and local area networks)of the mobile communication device are anchored in a gateway server,which server associates the mobile communication device with one commonphone number. Since the gateway server holds the common phone number allincoming calls are picked up by the gateway server, which then forwardsthe connection to either a wireless local area network, such as VoIP, ora wireless wide area network, such as GSM. Outgoing calls from themobile communication device are, likewise, made to the gateway serverwhich in turn forwards the connection to the callee. This two stagedialing, which is invisible to the user, is required for the mobilecommunication device running the client application to freely move thecall between networks.

The invention has mainly been described above with reference to a fewembodiments. However, as is readily appreciated by a person skilled inthe art, other embodiments than the ones disclosed above are equallypossible within the scope of the invention, as defined by the appendedpatent claims. Generally, all terms used in the claims are to beinterpreted according to their ordinary meaning in the technical field,unless explicitly defined otherwise herein. All references to“a/an/said/the [device, component, etc]” are to be interpreted openly asreferring to at least one instance of said device, component, etc.,unless explicitly stated otherwise. The steps of any method disclosedherein do not have to be performed in the exact order disclosed, unlessexplicitly stated.

1.-18. (canceled)
 19. A method in a server for handling a connectionbetween a mobile communication device and a second communication device,said server being connected to a wireless local area network and awireless wide area network, said method comprising: receiving a signalindicative of a status of the connectivity between said mobilecommunication device and said wireless local area network, and dependingon said connectivity status, controlling a sticky handover process,wherein in a case where the connectivity status of the connectionbetween the mobile communication device and the wireless local areanetwork is bad and the mobile communication device is connected to thewireless local area network, handing over the connection from thewireless local area network (130) to said wide area wireless network,and in a case where the connectivity status of the connection betweenthe mobile communication device and the wireless local area network isgood and the mobile communication device is not connected to thewireless local area network, handing over the connection to the wirelesslocal area network, associating said mobile communication device with awireless local area network address, associating said mobilecommunication device with a unique identity in a wireless wide areanetwork, and storing said address and said unique identity, receiving arequest for a connection from said mobile communication device to saidsecond communication device, in the case where the connectivity statusof the connection between said mobile communication device and thewireless local area network is good, initiating a connection betweensaid mobile communication device and said server via said wireless localarea network, and in the case where the connectivity status of theconnection between said mobile communication device and the wirelesslocal area network is bad, initiating a connection between said mobilecommunication device and said server via said wireless wide area networkestablishing a connection between said mobile communication device andsaid second communication device via said server so that all connectionsto and from the mobile communication device are anchored in the server,indicating the loss of a wide area network connection from a softwareclient of the mobile communication device to the user of the mobilecommunication device, and from the server to the user of the secondcommunication device, wherein the server initiates and establishes a newwireless wide area network connection from the server to the mobilecommunication device using the unique identity.
 20. Method according toclaim 19, wherein the sticky handover process further comprises in thecase the connectivity status of the connection between the mobilecommunication device and the wireless local area network is bad and themobile communication device is connected to the wireless local areanetwork: determining said unique identity of the mobile communicationdevice using the wireless local area network address of the mobilecommunication device, initiating said wireless wide area networkconnection from the server to the mobile communication device using saidunique identity, establishing a connection between said mobilecommunication device and said second communication device via saidserver, wherein the connection between the mobile communication deviceand the server is a connection in said wireless wide area network,terminating the wireless local area network connection between themobile communication device and the server, and in the case theconnectivity status of the connection between the mobile communicationdevice and the wireless local area network is good and the mobilecommunication device is not connected to the wireless local areanetwork, determining said wireless local area network address of themobile communication device using the unique identity of the mobilecommunication device, initiating said wireless local area networkconnection from the server to the mobile communication device using saidwireless local area network address, establishing a connection betweensaid mobile communication device and said second communication devicevia said server, wherein the connection between the mobile communicationdevice and the server is a connection in said wireless local areanetwork, and terminating the wireless wide area network connectionbetween the mobile communication device and the server.
 21. Methodaccording to claim 19, further comprising detecting that the connectionbetween the mobile communication device and the wireless local areanetwork is lost; determining said unique identity of the mobilecommunication device using the wireless local area network address ofthe mobile communication device; and as a consequence of said detectionusing said unique identity to perform said sticky handover of theconnection from the wireless local area network to the wireless widearea network.
 22. The method according to claim 21, further comprisingindicating to said second communication device a temporary loss ofconnection pertaining to said detection of a lost connection between themobile communication device and the wireless local area network.
 23. Themethod according to claim 19, further comprising: receiving a requestfor a connection from said second communication device to said mobilecommunication device, requesting a status signal from said wirelesslocal area network indicative of a connection between said server andsaid mobile communication device; initiating a connection between saidserver and said second communication device; in the case the mobilecommunication device is connected to said wireless local area network,initiating a connection between said mobile communication device andsaid server via said valid wireless local area network, and in the casethe mobile communication device is not connected to said wireless localarea network, initiating a connection between said mobile communicationdevice and said server via said wireless wide area network, andestablishing a connection between said mobile communication device andsaid second communication device via said server.
 24. Method accordingto claim 19, wherein the signaling between said mobile communicationdevice and said server utilizes GPRS in a case said mobile communicationdevice is connected to said server via a wireless wide area network. 25.The method according to claim 19, wherein traffic data communicationbetween said mobile communication device and said server utilizes GPRSin a case said mobile communication device is connected to said servervia a wireless wide area network.
 26. The method according to claim 19,wherein said signal indicative of the status of the connectivity betweenthe mobile communication device and the wireless local area networkpertains to at least one of: a position and movement of the mobilecommunication device, a collected statistics of lost and retainedconnections for the position of the mobile communication device, a biterror rate between the mobile communication device and the wirelesslocal area network, a signal strength between the mobile communicationdevice and the wireless local area network, a number of lost packetsbetween the mobile communication device and the wireless local areanetwork, a number of retransmitted packets between the mobilecommunication device and the wireless local area network, asignal-to-noise ratio between the mobile communication device and thewireless local area network, a jitter of the signal between the mobilecommunication device and the wireless local area network, and a latencyof the signal between the mobile communication device and the wirelesslocal area network.
 27. The method according to claim 19, wherein saidwireless local area network is one of a plurality of available wirelesslocal area networks comprising at least one of: any IEEE 802.11xnetwork, WiMAX, Bluetooth, said wireless wide area network comprising atleast one of: UMTS, GPRS, EDGE, GSM, and wherein said wireless localarea networks and said wireless wide area networks are prioritizedaccording to a specific order.